The royal males were not, however, the stars of the show at St James's Palace - that honour belonged to Tyke, a UK customs sniffer dog who has smelled out animal furs, coral, bear bile, a Rolls Royce with alligator hide upholstery and even plasters infused with tiger bone which smugglers were attempting to bring into the UK.

The illegal wildlife trade one of top five most lucrative illegal trades in world, worth $10bn a year.

As a patron of Tusk Trust, a conservation charity, Williamtravelled to Botswana in 2010 to raise awareness of the issue.

In a video message to the Convention on International Trade in Endangered Species of Wild Fauna in March 2013, Prince William said “we need to do more to combat this serious crime if we are to reverse the current alarming trends. If not, we could soon see some populations of these creatures or even entire species disappear from the wild. We simply must not let this catastrophe unfold.”

The conference was told that rhino horn is being sold as a hangover cure, and that illegal traders are buying up stocks now on the basis they will be worth more in the future when the animals are extinct.